The goal of this contract is to provide support of National Toxicology Program (NTP) hazard identification (or hazard assessment) activities targeted toward the prevention of diseases or adverse effects caused by environmental exposure to chemical or physical agents. This contract includes a varied array of test materials and classes of test materials that are to be tested via the inhalation route of exposure, some are vapors while others are liquid or solid aerosols. This contract includes prechronic studies to evaluate the fibrotic potential and lung burden of 6 abrasive blasting agents (ABA) which includes blasting sand, coal slag, garnet, crushed glass, steel grit, and specular hematite. Abrasive blasting agents are of human health concern becasue of their content of Si and as replacements for crystalline silica. The 14-day studies have been completed and reported for all ABAs except steel grit. Steel grit studies will not be conducted because the bulk material cannot be milled to meet study needs. Thirty-nine week fibrogenicity studies with blasting sand and specular hematite have been conducted and reported. In addition this contract includes 14-day and 90-day toxicity studies for 9 metal working fluids (MWF) (Cimstar 3800, Trim SC210, Clearedge 6584, Cimtech 310, Syntilo 1023, Trim 229, Superedge 6768, Cimperial 1070, and Trim VX. MWFs are used extensively in occupational settings and present a possible heal risk to individuals using them. The 14-day studies were canceled and Trim SC210, Trim VX , Cimstar 3800, and Syntillo 1023 went directly to 90-day studies which have been completed and reported. The in-life portion of the Cimstar 3800 2-year studies is concluded and in histopathology while the 2-year studies of Trim VX are in-life. The contract also includes 14-day and 2-year studies of antimony trioxide. Antimony trioxide has been shown to be a carcinogen in some rodent species;however better controlled exposures and additional species need to be utilized to determine conclusively the carcinogenic potential of antimony trioxide so that the results can be used in human risk assessment. The 14-day studies have been completed and reported and the 2-year study in-life portion is ongoing. The contract also includes 90-day studies of C60 fullerene nanomaterials of 50nm and 1 micron sizes which have been completed and reported in FY-09. The contract also includes testing three artificial butter flavoring agents (ABAs, acetoin, 2,3-pentanedione, and 2,3-butanedione) in 14- day (acetoin), 90-day studies (acetoin, 2,3-pentanedione, and 2,3-butanedione), and 2-year studies of (2,3-butanedione). ABAs have been linked to occupational exposure and human health effects including bronchiolitis obliterans. Animal studies are needed to determine the potential for human health effects to individual ABAs. The 2,3-butanedione and acetoin 90-day studies have been completed and reported. The 2-year studies of 2,3-butanedione have been started. The 2,3-pentanedione 90-day study is currently in the exposure generation and monitoring phase. The contract also includes testing ortho-phthalaldehyde (OPA) in 90-day studies which were completed in FY-09. OPA is being utilized as a replacement for the known rodent carcinogen gluteraldehyde therefore animal toxicity data is needed to determine potential for human heal effects with OPA. The contract includes 90-day studies of p-chloro-a,a,a-trifluorotoluene (PCTFT). PCTFT is used extensively in the synthesis of a number of organic chemicals and there is concern with its increased use that there will be enhanced release to the atmoshphere. The 90-day study has been completed and reported. Keywords lung burden, fibrosis, toxicity and carcinogenicity, metal working fluids, abrasive blasting agents, artificial butter flavorings, antimony trioxide, ortho-phthalaldehyde